Tension bar bearing for looms



June 1, 1965 Filed May 14, 1962 w. ENGELS 3,186,441

TENSION BAR BEARING FOR LOOMS 2 Sheets-Sheet 1 2'7 25 F I l INVENIOR WALTER ENGELS BY l ATTORNEY June 1, 1965 w. ENGELS 3,186,441

TENSION BAR BEARING FOR LQOMS Filed May 14, 1962 2 Sheets-Sheet 2 FIG. 5.

32 ATTORNEY United States Patent 3,186,441 TENSION BAR BEARING FOR LOOMS Walter Engels, Tryon, N.C., assignor to Southern Machinery Company, Greer, S.C., a corporation of South Carolina Filed May 14, 1962, Ser. No. 194,543 4 Claims. (Cl. 139114) This invention relates to improvements in looms and more particularly to an improved tension bar bearing for looms.

As is well known, loom let-01f mechanisms are sensitive variable speed transmission devices which accurately control the velocity and the tension of the warp yarns being unwound from the loom beam. The let-oh mechanism operates in response to variations in tension on the whip roll of the loom which engages the warp yarns directly as they pass upwardly from the beam. The whip roll proper is carried by a pair of generally horizontal arms near and above the opposite ends of the loom beam and these arms in turn are secured to a rock shaft known also as a tension shaft or bar. The tension bar is rockably journa-led in conventional practice in bearings or pillow blocks on a fixed bracket structure mounted to the adjacent end loom frames. The tension bar or shaft is oscillated or rocked by generally horizontal tension arms, having their ends pivotally secured to generally vertical conventionally open and exposed, they frequently become tension links which extend downwardly adjacent the outer sides of the loom end frames for connection with the clogged with lint which adds to bearing wear and interferes with the smooth and accurate operation of'the leton mechanism, which is one of the more sensitive and critical loom components, and must operate in response to slight variations in warp tension, transmitted through the whip roll.

Accordingly, it is the object of this invention to provide a tension bar bearing which is virtually frictionless and therefore subject to minimum wear, and which bearing is mounted in a vibration-free manner within a flexible enclosure, which also serves to prevent lint and other foreign matter from entering the bearing structure.

Another object is to provide a tension bar bearing which vis economical to manufacture, reliable and eflicient in operation, trouble-free, easy to install upon new or existing looms and requiring no significant alteration of conventional 'loom structure.

A further object is to provide a bearing device of the character mentioned which will not only greatly reduce wear, as stated, but will actually improve the operating eficiency of the let-oil mechanism and therefore the entire weaving operation.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawings, forming a part of this application and in which like numerals are employed to designate like parts throughout the same,

FIGURE 1 is a fragmentary partly diagrammatic side elevation of a loom including the tension bar bearing and associated elements according to the invention,

FIGURE 2 is an enlarged fragmentaryperspective View of the tension bearing and associated elements,

FIGURE 3 is a plan view of the bearing,

FIGURE 4 is a transverse vertical section taken on line 44 of FIGURE 3,

FIGURE 5 is a side elevation of the bearing removed from the loom and showing the bearing per se and its flexible cover, 7

FIGURE 6 is an end elevation of the bearing shown in FIGURE 5,

FIGURE 7 is a vertical section taken on line 7-7 of FIGURE 6, and

FIGURE 8 is a horizontal section taken on line 88 of FIGURE 6.

In FIGURES 1 and 2 of the drawings, the flexible cover or housing for the bearing has been removed for the purpose of illustration.

In the drawings, wherein for the purpose of illustration is shown a preferred embodiment of the invention, the numeral 10 designates one frame end of a conventional loom, having the usual rest 11 for a warp beam 12. A rigid horizontal projection 13 on the top of the frame end It) carries a fixed upstanding support bracket 14, for the whip roll 15, tension bar 16 and associated elements. The whip roll is supported at its opposite ends by short arms 17 and longitudinal shaft extensions 18, which rest in pockets 19 of outer support arms 20. The arms 20 are rigidly connected through their hub portions 21 with the rockable tension bar or shaft 16. The arms 20 lie inwardly of the support bracket 14 as shown.

The bracket 14 has an open top rectangular pocket 22 formed therein for the bearing structure of this invention presently to be described and this bearing structure is designated generally in the drawings by the numeral 23. The bearing structure 23 rockably supports the adjacent end of tension bar 16, and an end portion 24 of the tension bar projects outwardly of the bearing structure and bracket 14 and carries an enlarged splined head 25, rigid therewith, coupled to a mating splined head 26 of a vertically swingable tension arm 27, having its free end pivotally secured at 28 to the well-known depending generally vertical tension link 29, which extends downwardly for attachment at its lower end to the weighted scale beam of the loom let-off mechanism, not shown, which controls the unwinding of the warp yarns from the beam 12 and allows the Warp yarns to maintain a substantially constant tension and linear velocity. This mode of operation is all conventional and well known to those skilled in the art and it is fully described in the above-mentioned Hunt Patent 2,786,491.

The bearing structure 23 embodies a V-block or cradle 30 of rectangular external shape so as to conform to the shape of the rectangular pocket 22 of bracket 14, within which it is seated. The V-block 30 is formed of cast iron or the like and has a horizontal symmetrically formed V-shaped recess 31 formed in its top parallel to the axis of tension bar 16 and in vertical alignment therewith. The sides of the recess 31 form an included angle of approximately 90 degrees, and the bottom of the V-shaped recess has a small radius 32 of approximately ,5 of an .inch or the like.

Resting within the recess 31 is a bearing wedge 33 having an upper cylindrically-shaped portion 34 including a horizontal bore 35 to receive snugly the adjacent portion of the tension bar 16 and supporting the latter. Upwardly directed set screws 36 are provided in the top of the bearing wedge 33 to clampingly secure the latter to the tension bar 16 adjustably. The bearing wedge 33 further comprises a depending V-shaped or tapered rocker portion 37 having symmetrically formed inclined fiat side faces 38 which form an included angle of approximately degrees, so that the bearing wedge may rock about its lower end within the recess 31 for about 10 degrees on either side of true vertical. The lower end of the tapered rocker portion 37 has a small radius to interfit smoothly with the radius 32 so that no sharp edges are present. Upon rocking of the bearing wedge 33 in either direction about its lower end, the side faces 38 will ultimately abut the flat side faces of the recess 31 to positively limit the movement of the bearing wedge in either direction. The bearing wedge 33 may be formed of cast iron, brass, or other materials found suitable for long wear and sturdiness. The bearing structure requires no lubrication and there is a very small area of contact between the bearing wedge 33 and the V-block or cradle 30 adjacent the radius 32. The bearing structure consisting of the cradle 30 and wedge 33 bodily supports the tension bar 16 and all parts carried thereby and the tension bar rocks or oscillates bodily with the bearing wedge 33 under influence of the whip roll and tension link 29.

The entire bearing structure 23 is enclosed by a flexible cover or jacket 39 formed of rubber or rubber-like material. This cover serves a two-fold purpose. It excludes lint and other foreign material from entering between the wedge 33 and the recesses 31 and it provide-s a resilient or vibration dampening lining between the outer faces of the cradle and the rectangular pocket 22. The cover 39 conforms to the assembled configuration of the cradle 36 and bearing wedge 33 and has two apertures in the top thereof to receive the internally threaded bosses 40 on the top of the wedge 33 which accommodate the "set screws 36. The opposite sides 'of the cover 39, FIG- URE 7, also have openings 41 to receive the short tubular hub extensions 42 of the bearing wedge 33. At its other corresponding sides, FIGURE 4, just above the top of bracket 14 and at the elevation of the axis of tension bar 16, the flexible cover 39 has outwardly bowed hollow beads or corrugated portions 43 molded thereon to permit flexing of the cover at these regions during rocking of the wedge 33 without stretching the cover appreciably and without increasing the tension or resistance to rocking of the wedge 33. Except at these points, the flexible cover 39 preferably snugly engages the bearing structure and conforms to the assembled shape thereof and snugly engages the surfaces of the pocket 22 to form an antivibration cushion between the bearing structure 23 and pocket 22.

The operation of the bearing wedge 33 upon the V- block or cradle 30 is substantially frictionless, silent and substantially free of vibration, and lint and other foreign matter is excluded from the bearing structure as stated.

During the conventional loom operation which need not be described here, and which is well described in the mentioned Hunt patent, the bearing wedges 33 supporting the opposite end portions of tension bar 16 rock freely back and forth upon the cradles 30 and within the confines of the V-shaped recesses 31. Variations in warp tension are transmitted in the usual manner through the whip roll 15 and tension bar 16 to the tension arm 27 and then to the tension link 29 which regulates the let-off mechanism as described in the Hunt patent and as well known to those skilled in the art. The improved bearing structure greatly reduces wear as compared to conventional tension shaft bearings and renders the let-off mechanism more sensitive and reliable in its operation and this is accomplished without the use of expensive ball bearings, roller bearings or like frictionless bearings which require lubrication and very close machining tolerances on the parts with which they are associated. These problems are allovercome with the present bearing structure, and :the same is economical to construct and adjustable to compensate for minor dimensional variations in shaft alignment and the like.

It is to be understood that the form of the invention ing a supporting bracket having an upwardly opening substantially rectangular pocket formed therein, a relatively stationary block seated within said pocket and having an exterior shape conforming substantially to the cross sectional shape of said pocket and also having an upwardly opening symmetrical V-shaped recess, a downwardly tapering symmetrical V-shaped wedge engaging within said V-shaped recess and defining an included angle between its converging sides which is substantially less than the included angle defined by the sides of said recess, said wedge having a through bore transversely thereof above said bracket and block adapted to support a tension bar, and a relatively thin walled flexible jacket substantially covering and enclosing the block and wedge and including a lower portion disposed between the interior surfaces of said pocket and the exterior surfaces of said block for resiliently cushioning the latter, said jacket being yieldable and adapted to flex during rocking movement of the wedge upon said block, said jacket excluding foreign matter from entering between said block and wedge during operation of the bearing structure.

2. The invention as defined by claim 1, and wherein said jacket is provided near and above the tops of said'block and bracket and on opposite sides of said wedge with a pair of hollow corrugations to allow ready flexing of the jacket during rocking of the wedge.

3. The invention as defined by claim 2, and wherein said Wedge has tubular hub extensions on opposite sides thereof above said block and said jacket is provided in corresponding opposite sides with openings to snugly receive said hub extensions.

4. In a loom, a tension bar support bracket having an upwardly opening rectangular pocket, a complementally shaped block disposed within said pocket and having an upwardly opening V-shaped recess including sides spaced apart approximately degrees angularly and being symmetrical with respect to a vertical center line through the bottom of said recess, a downwardly tapering wedge rockably mounted within said recess and having downwardly converging sides spaced apart approximately 70 degrees angularly and being symmetrical with respect to said vertical center line, said wedge having a through bore above said block parallel to said recess for receiving and supporting a loom tension bar, and a relatively thin walled flexible jacket for said block and wedge and substantially enclosing the same to exclude lint from said recess and having slackened side wall portions above said block on opposite sides of said wedge to substantially eliminate stretching of the jacket during rocking of the wedge upon said block, said jacket including a lower por- ,tion interposed snugly between the opposed surfaces of said pocket and block and forming an anti-vibration lining for said pocket to cushion the block and insulate it from shocks.

References Iited by the Examiner UNITED STATES PATENTS DONALD W. PARKER, Primary Examiner.

RUSSELL C. MADER, Examiner. 

1. A TENSION BAR BEARING STRUCTURE FOR LOOMS COMPRISING A SUPPORTING BRACKET HAVING AN UPWARDLY OPENING SUBSTANTIALLY RECTANGULAR POCKET FORMED THEREIN, A RELATIVELY STATIONARY BLOCK SEATED WITHIN SAID POCKET AND HAVING AN EXTERIOR SHAPE CONFORMING SUBSTANTIALLY TO THE CROSS SECTIONAL SHAPE OF SAID POCKET AND ALSO HAVING AN UPWARDLY OPENING SYMMETRICAL V-SHAPED RECESS, A DOWNWARDLY TAPERING SYMMETRICAL V-SHAPED WEDGE ENGAGING WITHIN SAID V-SHAPED RECESS AND DEFINING AN INCLUDED ANGLE BETWEEN ITS CONVERGING SIDES WHICH IS SUBSTANTIALLY LESS THAN THE INCLUDED ANGLE DEFINED BY THE SIDES OF SAID RECESS, SAID WEDGE HAVING A THROUGH BORE TRANSVERSELY THEREOF ABOVE SAID BRACKET AND BLOCK ADAPTED TO SUPPORT A TENSION BAR, AND A RELATIVELY THIN WALLED FLEXIBLE JACKET SUBSTANTIALLY COVERING AND ENCLOSING THE BLOCK AND WEDGE AND INCLUDING A LOWER PORTION DISPOSED BETWEEN THE INTERIOR SURFACES OF SAID SOCKET AND THE EXTERIOR SURFACES OF SAID BLOCK FOR RESILIENTLY CUSHIONING THE LATTER, SAID JACKET BEING YIELDABLE AND ADAPTED TO FLEX DURING ROCKING MOVEMENT OF THE WEDGE UPON SAID BLOCK, SAID JACKET EXCLUDING FOREIGN MATTER FROM ENTERING BETWEEN SAID BLOCK AND WEDGE DURING OPERATION OF THE BEARING STRUCTURE. 